(1) Field of the Invention
The present invention relates to a novel and useful bioactive composite material for prosthetic purposes, to a process of making same, and to the use of the resultant material in dental and bone surgery.
(2) Description of the Prior Art
In order to fix, i.e. firmly attach, for instance, endoprostheses and other bone replacements in the animal or human body it is known to use a so-called "bone cement" consisting of a plastic having a base of methacrylate. For instance, in the "Zeitschrift fuer Orthopaedie" vol. 112 (1974), pages 419-426, there is described a plastic "Palakav" which contains silica gels in addition to methyl methacrylate and an organic catalyst. The ratio of methyl methacrylate to silica is 58:42 in said bone cement. The inorganic gels added to said cement serve merely as filler for the plastic matrix.
Although with the use of this composite material there have already been achieved more favorable bonding effects in the sense of a micro-meshing effect of the "Palakav" on the adjoining bone substances than with the bone cements previously used such as, for instance, "Palacos," said known bone cement is merely able to bring about a certain macro-anchoring or -meshing effect with the adjoining bone substance. It has not been possible, however, to solve with the composite materials known up to the present time the basic problem of achieving fully satisfactory anchoring or bonding between the replacement material and the bone wall in the sense of stable, chemical, principal valence-like bondings which are capable of withstanding to a substantial extent even continuous compression, tension, shear, and/or torsional stresses.